In this work, a route to synthesize bioadditives through H₄SiW₁₂O₄₀-catalyzed levulinic acid esterification reactions with alcohols of short chain at room temperature was assessed. Among the Brønsted acids assessed (i.e., sulfuric, p-toluenesulfonic, silicotungstic, phosphomolybdic and phosphotungstic acids), H₄SiW₁₂O₄₀ was the most active and selective catalyst. High conversions (ca. 90%) and selectivity (90–97%) for alkyl levulinates with carbon chain size ranging from C₆ to C₁₀ were obtained. The effect of main reaction parameters was studied, with a special focus on the reaction temperature, stoichiometry of reactants, concentration and nature of the catalyst. Insights on reaction mechanism were done and the activity of heteropoly catalysts was discussed based on acid strength and softness of the heteropolyanions. The use of renewable raw material, the mild reaction conditions (i.e., room temperature), and a recyclable solid catalyst are the some of the positive features of this process. The alkyl levulinates obtained are renewable origin bioadditives that can be blended either to gasoline or diesel.

Graphical Abstract

中文翻译：

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室温下H 4 SiW 12 O 40催化的乙酰丙酸的酯化反应用于生产燃料生物添加剂

在这项工作中，评估了在室温下通过H ₄ SiW ₁₂ O ₄₀催化的乙酰丙酸酯化与短链醇合成生物添加剂的途径。在所评估的布朗斯台德酸（即硫酸，对甲苯磺酸，硅钨酸，磷钼酸和磷钨酸）中，H ₄ SiW ₁₂ O ₄₀是最具活性和选择性的催化剂。碳链大小为C ₆至C _10的乙酰丙酸烷基酯的高转化率（约90％）和选择性（90-97％）获得了。研究了主要反应参数的影响，特别关注反应温度，反应物的化学计量，催化剂的浓度和性质。对反应机理进行了深入的研究，并基于酸强度和杂多阴离子的柔软性讨论了杂多催化剂的活性。使用可再生原料，温和的反应条件（即室温）和可回收的固体催化剂是该方法的一些积极特性。获得的乙酰丙酸烷基酯是可再生来源的生物添加剂，可以与汽油或柴油共混。

图形概要